Indirect Dark Matter Detection from Dwarf Satellites: Joint Expectations from Astrophysics and Supersymmetry

Abstract

We present a general methodology for determining the gamma-ray flux from annihilation of dark matter particles in Milky Way satellite galaxies, focusing on two promising satellites as examples: Segue 1 and Draco. We use the SuperBayeS code to explore the best-fitting regions of the Constrained Minimal Supersymmetric Standard Model (CMSSM) parameter space, and an independent MCMC analysis of the dark matter halo properties of the satellites using published radial velocities. We present a formalism for determining the boost from halo substructure in these galaxies and show that its value depends strongly on the extrapolation of the concentration-mass (c(M)) relation for CDM subhalos down to the minimum possible mass. We show that the preferred region for this minimum halo mass within the CMSSM with neutralino dark matter is ~10^-9-10^-6 solar masses. For the boost model where the observed power-law c(M) relation is extrapolated down to the minimum halo mass we find average boosts of about 20, while the Bullock et al (2001) c(M) model results in boosts of order unity. We estimate that for the power-law c(M) boost model and photon energies greater than a GeV, the Fermi space-telescope has about 20% chance of detecting a dark matter annihilation signal from Draco with signal-to-noise greater than 3 after about 5 years of observation.

References in corpus (21)

• Bayes in the sky: Bayesian inference and model selection in cosmology
• The Kinematics of the Ultra-Faint Milky Way Satellites: Solving the Missing Satellite Problem
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• A common mass scale for satellite galaxies of the Milky Way
• What mass are the smallest protohalos?
• Effects of cold dark matter decoupling and pair annihilation on cosmological perturbations
• Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments
• Detecting dark matter WIMPs in the Draco dwarf: a multi-wavelength perspective
• Early supersymmetric cold dark matter substructure
• Fitting the Gamma-Ray Spectrum from Dark Matter with DMFIT: GLAST and the Galactic Center Region
• Stellar kinematics and metallicities in the Leo I dwarf spheroidal galaxy -- wide field implications for galactic evolution
• Stellar kinematics in the remote Leo II dwarf spheroidal galaxy -- Another brick in the wall
• Dark Matter Annihilation in Substructures Revised
• Implications for the Constrained MSSM from a new prediction for b to s gamma
• Bayesian Selection of sign(mu) within mSUGRA in Global Fits Including WMAP5 Results
• Determining the Nature of Dark Matter with Astrometry
• Dark Matter Halos with Cores from Hierarchical Structure Formation
• Prospects for direct dark matter detection in the Constrained MSSM
• On prospects for dark matter indirect detection in the Constrained MSSM
• Dark Matter annihilation in Draco: new considerations of the expected gamma flux
• Dark Matter: the Connection with Gamma-Ray Astrophysics

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• Prospects for dark matter detection with IceCube in the context of the CMSSM